Pharmacokinetic study and neuropharmacological effects of atractylenolide â ¢ to improve cognitive impairment via PI3K/AKT/GSK3ß pathway in intracerebroventricular-streptozotocin rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional Chinese herbal remedy Atractylodes macrocephala Koidz is renowned for its purported gastrointestinal regulatory properties and immune-enhancing capabilities. Atractylenolide III (ATL III), a prominent bioactive compound in Atractylodes macrocephala Koidz, has demonstrated significant pharmacological activities. However, its impact on neuroinflammation, oxidative stress, and therapeutic potential concerning Alzheimer's disease (AD) remain inadequately investigated. AIM OF THE STUDY: This study aims to assess the plasma pharmacokinetics of ATL III in Sprague-Dawley (SD) rats and elucidate its neuropharmacological effects on AD via the PI3K/AKT/GSK3ß pathway. Through this research, we endeavor to furnish experimental substantiation for the advancement of novel therapeutics centered on ATL III. MATERIALS AND METHODS: The pharmacokinetic profile of ATL III in SD rat plasma was analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). AD models were induced in SD rats through bilateral intracerebroventricular (ICV) administration of streptozotocin (STZ). ATL III was administered at doses of 0.6 mg/kg, 1.2 mg/kg, and 2.4 mg/kg, while donepezil (1 mg/kg) served as control. Cognitive function assessments were conducted employing behavioral tests including the Morris Water Maze and Novel Object Recognition. Neuronal pathology and histological changes were evaluated through Nissl staining and Hematoxylin-Eosin (HE) staining, respectively. Oxidative stress levels were determined by quantifying malondialdehyde (MDA) content and total superoxide dismutase (T-SOD) activity. Molecular docking analysis was employed to explore the direct binding between ATL III and its relevant targets, followed by validation using Western blot (WB) experiments to assess the expression of p-Tau, PI3K, AKT, GSK3ß, and their phosphorylated forms. RESULTS: Within the concentration range of 5-500 ng/mL, ATL III demonstrated exceptional linearity (R2 = 0.9991), with a quantification limit of 5 ng/mL. In male SD rats, ATL III exhibited a Tmax of 45 min, a t1/2 of 172.1 min, a Cmax of 1211 ng/L, and an AUC(0-t) of 156031 ng/L*min. Treatment with ATL III significantly attenuated Tau hyperphosphorylation in intracerebroventricular-streptozotocin (ICV-STZ) rats. Furthermore, ATL III administration mitigated neuroinflammation and oxidative stress, as evidenced by reduced Nissl body loss, alleviated histological alterations, decreased MDA content, and enhanced T-SOD activity. Molecular docking analyses revealed strong binding affinity between ATL III and the target genes PI3K, AKT, and GSK3ß. Experimental validation corroborated that ATL III stimulated the phosphorylation of PI3K and AKT while reducing the phosphorylation of GSK3ß. CONCLUSIONS: Our results indicate that ATL III can mitigate Tau protein phosphorylation through modulation of the PI3K/AKT/GSK3ß pathway. This attenuation consequently ameliorates neuroinflammation and oxidative stress, leading to enhanced learning and memory abilities in ICV-STZ rats.

Association between stroke and venous leg ulcers: A Mendelian randomization study.

To investigate any potential bidirectional causal relationships between stroke and venous leg ulcers (VLUs), Mendelian randomization (MR) analyses were carried out in this study. The exposure factor was stroke, the outcome factor was VLUs. The two-sample MR study was carried out based on the online analysis platform (http://app.mrbase.org/). The association of stroke and VLUs was analysed via methods of Inverse Variance Weighted (IVW), Weighted Median, MR-Egger and weighted mode. IVW method suggested no association between stroke and VLUs ((ß 1.06; SE 9.321; p = 0.9095)). Weighted median estimator (ß 5.906; SE 11.99, p = 0.6223), MR-Egger (ß -0.8677; SE 21.89; p = 0.9691) and weighted mode (ß 9.336; SE 17.77; p = 0.6089) showed consistent results. Conversely, evidence indicating that the presence of VLUs increased the risk of stroke was lacking. According to this MR study, there is no causal connection between stroke and VLUs, which suggests that therapies targeting stroke may not be effective against VLUs.

Association between venous leg ulcers and chronic heart failure: A Mendelian randomization study.

An association between venous leg ulcers (VLU) and chronic heart failure (CHF) has been suggested by observational research. This study used Mendelian randomization (MR) methods to look into any possible bidirectional causal links between VLU and CHF. The 'TwoSampleMR' R package was employed for MR analyses. The association of VLU and CHF was assessed via methods of inverse variance weighted (IVW), weighted mode, MR Egger and weighted median. Results of IVW suggested no association between VLU and CHF (ß 0.008356; SE 0.01889; p = 0.6582). The weighted median estimator (ß -0.005777; SE 0.02059, p = 0.7791), MR-Egger (ß -0.08955; SE 0.04557; p = 0.07296) and weighted mode (ß -0.01202; SE 0.02467; p = 0.6341) showed consistent results. Conversely, evidence indicating that the presence of CHF increased the risk of VLU was lacking. In conclusion, there is no bidirectional causal relationship between VLU and CHF. Further studies are required to validate the findings of this study.

Osthole/borneol thermosensitive gel via intranasal administration enhances intracerebral bioavailability to improve cognitive impairment in APP/PS1 transgenic mice.

Alzheimer's disease (AD) poses a significant threat to the global elderly population. Traditional Chinese medicine (TCM) has been widely utilized in the treatment of AD. Osthole, a bioactive ingredient classified as an "emperor" in many TCM formulas, has been demonstrated to effectively alleviate AD symptoms. However, its low bioavailability in the brain has limited its clinical application. This study aimed to increase the intracerebral bioavailability of osthole by using borneol as a "courier," based on the classical "Emperor-Minister-Assistant-Courier" model, and to investigate the enhanced pharmacological performance of osthole on AD. Results indicated that a suitable in situ thermosensitive gel matrix for intranasal administration mixed with osthole and borneol consists of P407 at 20%, P188 at 7%, and PEG300 at 6%. The concentration of osthole in the cerebrospinal fluid increased almost tenfold after intranasal administration of osthole/borneol compared to oral administration. Mechanisms showed that borneol as a "courier" opened up intercellular space and loosened the tight junctions of the nasal mucosa by suppressing ZO-1 and occludin expression, thereby expediting the nose-to-brain route and guiding osthole as "emperor" to its target in the brain. Osthole assisted by borneol demonstrated significantly improved efficiency in suppressing cleaved caspase-3 expression, increasing the Bcl-2/Bax ratio, improving T-SOD and catalase expression, reducing malondialdehyde levels, inhibiting neuron apoptosis, and decreasing Aß levels by inhibiting BACE1 expression to alleviate cognitive impairment in APP/PS1 mice compared to osthole alone. Overall, our study demonstrated that the intracerebral bioavailability of osthole profoundly improved with intranasal administration of osthole/borneol and provided a wider application of TCM for AD treatment with higher intracerebral bioavailability.

PARP-1 hyperactivation and reciprocal elevations in intracellular Ca2+ during ROS-induced nonapoptotic cell death.

The generation of reactive oxygen species (ROS) has been implicated in the pathogenesis of renal ischemia/reperfusion injury, and many other pathological conditions. DNA strand breaks caused by ROS lead to the activation of poly(ADP-ribose)polymerase-1 (PARP-1), the excessive activation of which can result in cell death. We have utilized a model in which 2,3,5-tris(glutathion-S-yl)hydroquinone (TGHQ), a nephrotoxic and nephrocarcinogenic metabolite of hydroquinone, causes ROS-dependent cell death in human renal proximal tubule epithelial cells (HK-2), to further elucidate the role of PARP-1 in ROS-dependent cell death. TGHQ-induced ROS generation, DNA strand breaks, hyperactivation of PARP-1, rapid depletion of nicotinamide adenine dinucleotide (NAD), elevations in intracellular Ca(2+) concentrations, and subsequent nonapoptotic cell death in both a PARP- and Ca(2+)-dependent manner. Thus, inhibition of PARP-1 with PJ34 completely blocked TGHQ-mediated accumulation of poly(ADP-ribose) polymers and NAD consumption, and delayed HK-2 cell death. In contrast, chelation of intracellular Ca(2+) with BAPTA completely abrogated TGHQ-induced cell death. Ca(2+) chelation also attenuated PARP-1 hyperactivation. Conversely, inhibition of PARP-1 modulated TGHQ-mediated changes in Ca(2+) homeostasis. Interestingly, PARP-1 hyperactivation was not accompanied by the translocation of apoptosis-inducing factor (AIF) from mitochondria to the nucleus, a process usually associated with PARP-dependent cell death. Thus, pathways coupling PARP-1 hyperactivation to cell death are likely to be context-dependent, and therapeutic strategies designed to target PARP-1 need to recognize such variability. Our studies provide new insights into PARP-1-mediated nonapoptotic cell death, during which PARP-1 hyperactivation and elevations in intracellular Ca(2+) are reciprocally coupled to amplify ROS-induced nonapoptotic cell death.